ANTHOZOA. 
69 
remark the numerous non-piunate tentacles (t), the cavities of which 
communicate with the general cavity (c), which is divided into 
compartments by septa (m), on the walls of which the gonads (g) are 
developed. The axis is occupied by the stomach (s), which com- 
municates below with the general cavity, and opens above by a mouth 
marked by a special slit ( od ) ; y? marks the point at which a chamber 
is in communication with its neighbour, and d is the lower surface of 
the disk. The specimens and explanatory labels in Case XIIIb may 
be found of assistance in understanding the structure of corals. 
As it is impossible to preserve in alcohol the beauty of form and 
colouring presented by Sea-Anemones, the aid of the artist has been 
called in, and sketches from life are shown on the walls. 
As in the Zoantharia, there may be no spicules, a horny skeleton, 
or a continuous calcareous skeleton ; but spicules scattered in the 
flesh are not known. 
Of the soft-bodied forms other than the well-known Sea-Anemone 
of the shore, attention should be directed to the remarkable Geri- 
anthus membranaceus (Fig. 8), which makes for itself a curious woven 
tube, open at either end. The effect of this is that, during a 
dredging operation, the Cerianthus generally succeeds in making his 
escape, and a mere empty tube is all that rewards the dredger. 
The Antipatharia have a purely horny skeleton, which encloses a 
central canal and is always spiny. This skeleton may be a single 
rod, as in Oirripathes, where it may attain a great height, or consist 
of a collection of straight rods, as in the remarkable forms from 
Mauritius, which has been called Antipathes robillardi ; or it 
may be more or less branched and form tufts or wide plates, as in 
Aphanipathes , or the branches may fuse with one another, as in 
Arachnopathes , an elegant example of which will be found by itself 
on the wall near the middle doors. The most common form is the 
tree-like A. abies (Fig. 9). 
According to the recent researches of Dr. Carlgren, the large 
black coral-like structure which forms such a conspicuous object 
opposite the eastern door to this Gallery, and which is known as 
Gerardia savalia (Fig. 10), has been wrongly regarded as an Anti- 
patharian or horny coral. It is, according to the Swedish naturalist, 
allied by the structure of its polyps to Parazoanthus, and must 
therefore be placed with the otherwise soft-bodied Zoantharia. The 
specimen here exhibited, with a suitable explanatory label, is sur- 
prisingly large, and nothing like it is possessed by any other Museum 
of Natural History. 
